Vast pools of /what/ though?
It seems, at present, that energy is more of a constraint on civilization than matter.
With unlimited cheap energy, there's enough material to do most anything we might reasonably want.
It's likely to cost $thousands/kg to bring materials back from beyond Earth orbit. There are only a handful of elements valuable enough, and that's if they existed in pure form.
Hypothetically, if an asteroid made of pure gold existed, and if a Cargo Dragon atop a Falcon Heavy had enough delta-V to make it there and back with a couple of tonnes, it might break even, but all of this is doubtful.
Most valuable minerals are worth hundreds to low thousands of dollars per kg, so you need a launcher that can bring back a ton of rock for $1M - and not from LEO, you probably need to escape Earth's gravity and get back again.
The physics and engineering are proven, but the economics? Unlikely.
Put another way, you can mine a heck of a lot of Earth rocks with a rocket's worth of kerosene.